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GNAM and OHP: Monitoring Tools for the ATLAS Experiment at LHC. M. Della Pietra , P. Adragna, D. Cimino, A. Dotti, R. Ferrari, G. Gaudio, C. Roda, D. Salvatore, W. Vandelli, P. F. Zema IEEE NSS – San Diego October, 30th 2006. Outline. ATLAS @ LHC: Trigger and DAQ Systems
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GNAM and OHP: Monitoring Tools for the ATLAS Experiment at LHC M. Della Pietra, P. Adragna, D. Cimino, A. Dotti, R. Ferrari, G. Gaudio, C. Roda, D. Salvatore, W. Vandelli, P. F. Zema IEEE NSS – San Diego October, 30th 2006
Outline • ATLAS @ LHC: Trigger and DAQ Systems • Online monitoring architecture • Monitoring tools: • GNAM – framework for online histogram production • OHP – Online Histogram Presenter • ATLAS Commissioning phase • Conclusions M. Della Pietra - N07-6 - IEEE NSS 2006
Muons detectors Trackingdetectors Calorimeters ATLAS @ LHC p-p collisions @ 7+7 TeV Bunch crossing every 25 ns 40 MHz collisions 75 kHz 1st level trigger O(100 Hz) stored events 44 m long, 22 m high, 7000 tons 140 M channels, O(1MB)/event M. Della Pietra - N07-6 - IEEE NSS 2006
Trigger and DAQ in ATLAS 1,6 Mb/25 ns M. Della Pietra - N07-6 - IEEE NSS 2006
Data Quality Monitoring Event Dump Histogram Presenter Athena Monitoring Monitoring Data Archive Analysis Monitoring Services Archiving Displays Frameworks Information Monitors Web Monitoring Archive Browser GNAM Gatherer Histograms, Events, Messages, Counters, Etc… Histograms Histograms, Counters, Etc… Events Histograms Error Reporting Message Reporting Online Histogramming Event Monitoring Information Service ATLAS Online Monitoring System M. Della Pietra - N07-6 - IEEE NSS 2006
GNAM: A Monitoring Framework • GNAM is an online monitoring framework that executes specific plug-ins providing them with two interfaces: • Input: allows to read physics events from different sources (i.e. main DataFlow system, Event Monitoring stream, event file, etc.) • Output: allows to publish histograms to the Online Histogram Service M. Della Pietra - N07-6 - IEEE NSS 2006
Calorimeter Muon detector Inner detector GNAM: Core & Plug-ins Detector Plug-ins Asynchronous commands from OHP (Reset, Update, …. Event Monitoring Data Fragments Histograms Synchronous Commands Online Histogramming GNAM Core DAQ M. Della Pietra - N07-6 - IEEE NSS 2006
GNAM: Detector Plug-in • Each ATLAS Subdetector (Muons, Calorimeters, etc.) can provide at least two shared-libraries, loaded during the DAQ configuration to: • decode its own data fragment • book and fill its histograms, tagging them with priorities (SHIFT, EXPERT and DEBUG mode) • This decoupling allows to easily produce combined histograms between different subsystems • A special library could be written to dump each single decoded event on a circular buffer, read by an event-display software to show it “online” M. Della Pietra - N07-6 - IEEE NSS 2006
OHP: Online Histogram Presenter • OHP could be thought as a client application of the OH Service • Its role is to display histograms produced by the ATLAS Monitoring components in a user-friendly graphical application within ATLAS online environment. M. Della Pietra - N07-6 - IEEE NSS 2006
OHP main features • It subscribes to the desired histograms and get notifications from OH whenever they are updated • It allows to browse all the histograms (expert mode) or configure a set of histograms to be displayed in tabs (shifter mode) • It allows to perform actions on histograms (as reset, rebin, update, fitting, zooming) • It manages reference histograms • It reduces the network traffic using a cache system M. Della Pietra - N07-6 - IEEE NSS 2006
OHP Architecture Histogram receiver Cache Only histogram “on-focus” are updated Core Filtering OHP and OHS may run on different machines connected via network Configurable GUI M. Della Pietra - N07-6 - IEEE NSS 2006
OHP: GUI M. Della Pietra - N07-6 - IEEE NSS 2006
GNAM & OHP in ATLAS Commissioning OHP snapshot during a run with cosmics Histograms produced by GNAM – Tile Calorimeter Library A cosmic event in the muon detectors decoded by a GNAM library and displayed “online” by an event display M. Della Pietra - N07-6 - IEEE NSS 2006
Conclusions • The HUGE amount of data in the LHC experiments need to be monitored all along the dataflow by flexible and scalable monitoring tools • GNAM is a monitoring framework within the ATLAS TDAQ system that allows detector plug-ins to decode and analyse data and to publish histograms on a network • OHP is a client graphical application to present histograms to shifters in a flexible and interactive way • Both tools are extensively used during the commissioning of detectors • This commissioning period will be a benchmark for GNAM and OHP (as well as the whole monitoring system) for the development of new features M. Della Pietra - N07-6 - IEEE NSS 2006